Needle protection device comprising a distal protection element and a proximal protection element

ABSTRACT

A needle protection device detachably fixed to an injection appliance includes a needle, a needle holder from which a needle injection section of the needle projects distally and a needle connection section of the needle projects proximally, a distal needle protection element connected to the needle holder movable in the distal direction from a release position to a protection position and arranged behind the needle injection section in the release position and overlapping the needle injection section and distal end of the injection needle in the protection position, a proximal needle protection element connected to the needle holder movable from a release position and arranged behind the needle connection section into a protection position and overlapping the needle connection section and proximal end of the injection needle, and a blocking device which blocks movement of the proximal needle protection element from the protection position into the release position.

CROSS-REFERENCED RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/399,700, filed Mar. 6, 2009, which is a continuation of InternationalPatent Application No. PCT/CH2007/000414 filed Aug. 22, 2007, whichclaims priority to German Patent Application No. DE 10 2006 042 233.3filed Sep. 6, 2006, the entire contents of both of which areincorporated herein by reference.

BACKGROUND

The invention relates to devices for injecting, delivering, infusing,dispensing or administering a substance, and to methods of making andusing such devices. More particularly, it relates to a needle guarddevice which is releasably attached to or can be attached to aninjection device. The injection device may be used to administermedicaments, for example insulin, and for self-administration, i.e. bypatients who administer the relevant medicament themselves. Theinjection device may be configured for repeated use and to allow thedose of product to be administered to be set or selected. Moreparticularly, the injection device may be an injection device of thetype used to treat diabetes or otherwise.

To prevent the risk of infections, needle guard devices have beendeveloped which enable an injection device to be used only once. Aneedle guard device of this type is known from patent specification WO01/91837 A1, for example. The injection needle extends through theneedle holder and is fixedly secured by the needle holder. It has aninjection portion extending beyond the needle holder in the distaldirection and a connecting portion extending beyond the needle holder inthe proximal direction.

SUMMARY

One object of the present invention is to provide needle guard devicesthat increase the level of safety which can be achieved by using suchdevices and to prevent injury due to piercing.

In one embodiment, the present invention comprises a needle guard whichcan be releasably attached to an injection device. In one embodiment,the needle guard comprises an injection needle and a needle holderholding the injection needle, from which the needle projects by a needleinjection portion in the distal (front or forward) direction and fromwhich the needle projects by a needle connecting portion in the proximal(rear) direction. The needle guard also has a distal needle guard forthe needle injection portion which is connected to the needle holder sothat it can move. The injection needle may extend through the needleholder and is fixedly secured by the needle holder. Alternatively, theneedle injection portion and the needle connecting portion may also beseparate needles, which are retained by the needle holder and connectedto one another to establish a fluid flow. However, the needle holder mayalso incorporate the two needle portions in a single piece.

When administering the substance or product to be administered, theneedle injection portion pierces the skin and/or tissue lyingsubcutaneously underneath. When a membrane is attached, providing atight seal at a distal outlet of a reservoir filled with the product tobe administered, the needle connecting portion pierces it. The distalneedle guard is able to move in the distal direction relative to theneedle holder from a released position as far as a guard position, suchas by spring force. When the needle guard assumes the released position,the injection needle sits or rests with its needle injection portionbeyond the needle guard in the distal direction. In the guard position,on the other hand, the needle guard overlaps the needle injectionportion as far as and including a distal (forward or injection end) endof the injection needle. In the initial state prior to using the devicefor the first time, the needle guard may assume a distal initialposition from which it can be moved into the released position.

In some embodiments, the distal needle guard is locked in the guardposition so that it can not be moved into the released position again.The lock may be established automatically when the needle guard hasreached the guard position, having moved in the distal direction. Apartfrom self-locking needle guard devices of this type, however, thepresent invention also generally relates to needle guard devices with adisplaceable distal needle guard which does not lock after an injection.In such designs, the needle guard is primarily used to block the view toremove the fear of the injection needle for a user administering theproduct himself.

As provided herein, in some embodiments, the needle guard devicecomprises a proximal needle guard, which is displaceably connected tothe needle holder. The proximal needle guard can be moved in theproximal direction out of a released position as far as a guardposition. In the released position, the needle connecting portionextends beyond the proximal needle guard in the proximal direction. Inthe guard position, the proximal needle guard overlaps the needleconnecting portion up to and including the proximal end of the injectionneedle. The needle guard device also has a lock mechanism for theproximal needle guard. As soon as the proximal needle guard has reachedthe guard position, having moved in the proximal direction, it isautomatically locked by the lock mechanism so that it is no longer ableto move back into the released position. Although needle guard deviceswith a distal guard are already known from the prior art, for example,from patent specification WO 01/91837 A1 mentioned above, as recognizedherein, the needle connecting portion can also cause piercing injuriesafter the respective needle guard device has been used and theembodiments disclosed herein eliminate this risk via the other needleguard which automatically locks in a guard position after the needleguard device in accordance with the present invention has been used,i.e. as the injection device is removed or after it has been removed.

In some embodiments, the needle guard device has a fixing mechanismconfigured as a fixing sleeve to provide a releasable connection to theinjection device. The fixing mechanism may co-operate with fixing meansassociated with or disposed externally on the injection pen. It may be athreaded or bayonet sleeve or a snap-fit, catch-fit or clip-on sleeve,for example. In such designs, the fixing device surrounds the needleconnecting portion in a manner conventionally used for needle guarddevices. However, the known fixing devices are usually so large in termsof their diameter that the user can easily reach the needle tip of theneedle connecting portion with the finger and injure himself. The distalneedle guard provided herein, however, is disposed closer to the needleconnecting portion than with other fixing mechanisms, and the distancemeasured transversely to the needle connecting portion is short, suchthat the user does not come into contact with the proximal needle tip ifhe touches the proximal end of the proximal needle guard. As a result,the manufacturer also has greater freedom in terms of the design of thefixing mechanism because it offers an additional protective functioncompared with the other sleeve-shaped, fixing mechanisms, but in thiscase protecting against piercing injuries can be obtained by theproximal needle guard.

In some embodiments, a needle guard device in accordance with thepresent invention has a spring element, which biases the proximal needleguard in the proximal direction by a spring force. The spring elementmay be supported directly on the proximal needle guard but may also acton the needle guard via one or more intermediate elements. In suchdesigns, when the needle guard device is removed from the injectiondevice, the needle guard is moved into the guard position by springforce. In other variants, the same spring element also acts in thedistal direction on the distal needle guard directly or via one or moreintermediate elements. In further embodiments, the spring element issupported at one end on the distal needle guard and at the oppositelylying end on the proximal needle guard. Depending on its function, thespring element may be a compression spring, such as a helical spring. Inalternative embodiments, the proximal needle guard is not moved into theguard position by spring force, but by a retaining mechanism comprisinga retaining holder on the proximal needle guard and a retaining holderon the injection device or product reservoir, which automatically moveinto a retaining engagement when the needle guard device and injectiondevice are connected, which causes the proximal needle guard to be movedfrom the released position into the guard position when the needle guarddevice is released. Once the proximal needle guard has assumed its guardposition, the retaining engagement automatically releases when theneedle guard device is substantially or completely detached from theinjection device.

In some embodiments, the lock mechanism comprises at least two lockingelements, a first locking element formed on the needle holder or, in thesituation where the parts are separate, connected to the needle holder,and a second locking element formed on the proximal needle guard or, inthe situation where the parts are separate, connected to the needleguard. At least one of the locking elements may be able to movetransversely to the longitudinal direction of the injection needleagainst a resistant or rebounding spring force. The relevant lockingelement itself may be inflexible, i.e. rigid, and in such embodiments isbiased by the rebounding spring force by a separate spring element.However, the relevant locking element may be elastic and may form anelastic bending beam. The rebounding spring force may be used to movethe locking element into the locked engagement with the other lockingelement. The locked engagement may be achieved by an elastic snappingmovement. In alternative embodiments, however, the lock mechanism may beprovided in the form of only rigid locking elements, i.e. they are notflexible. This being the case, however, the locking elements may need tobe moved into the locked engagement when the proximal needle guard movesinto the guard position. In such embodiments, the lock mechanism mayhave one or more slide guides, by which the locking elements areforcibly guided relative to one another into the locked engagement.

In some embodiments, the second locking element formed on the proximalneedle guard or connected to the needle guard may be guided outwardlyfrom the needle guard and co-operate with the first locking element bygripping the needle guard device, but the proximal needle guard mayextend through the needle holder in the distal or in the proximaldirection, at least in the guard position.

In one embodiment, the proximal needle guard assumes a proximal(rearward) initial position prior to using the needle guard device, fromwhich it is moved into the released position as the needle guard deviceis connected to the injection device. In a second embodiment, theproximal needle guard is already in the released position in the statein which the needle guard device is sold. In both embodiments, theneedle guard device comprises an unlocking element. In the firstembodiment, the unlocking element co-operates with the at least onelocking element, which can be displaced transversely to the longitudinaldirection of the injection device so that the locked engagement can beestablished during the movement out of the proximal initial positioninto the released position because the unlocking element is engaged withthe transversely moving locking element, which may also include thesituation in which it is engaged with the first and the second lockingelement in order to prevent the locked engagement. During the course ofthe injection, such as during piercing by the needle injection portionor as the needle injection portion is being pulled out of or has beenpulled out of the tissue, the engagement between the unlocking elementand locking element is automatically released so that the lockingelements are able to move into the locked engagement when the needleguard device is detached from the injection device. In the secondembodiment, during piercing by the injection needle, the unlockingelement is moved out of an unlocking position, in which it prevents theproximal needle guard from moving in the proximal direction, into aneutral position in which it permits such a movement and hence amovement into the guard position. The unlocking element of the secondembodiment may be rotatable and connectable to the needle holder so asto be rotatable about the injection needle.

The unlocking elements of both embodiments may be coupled with thedistal needle guard or may be automatically coupled with the distalneedle guard during piercing or as the injection needle is being pulledout of the tissue. In such designs, the distal needle guard causes theunlocking element to move out of the unlocking position into the neutralposition via the coupling. The coupling may be a driving engagement bywhich the distal needle guard drives the unlocking element with it asfar as the neutral position as it moves in the distal direction, i.e.during removal from the tissue. Alternatively, the slide guide may formthe coupling, in which case the slide guide converts the piercingmovement or the movement of extracting the distal needle guard into themovement of the unlocking element out of the unlocking position into theneutral position. As a result, the slide guide enables a linear piercingmovement or extraction movement of the distal needle guard to beconverted into a rotating movement of the unlocking element, forexample.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view onto a distal end face of an example of a needle guarddevice according to a first embodiment in accordance with the presentinvention;

FIG. 2 shows the needle guard device in a longitudinal section A-A;

FIG. 3 shows the needle guard device in a longitudinal section B-B;

FIG. 4 shows the needle guard device in a longitudinal section C-C;

FIG. 5 illustrates components of the needle guard device aligned along alongitudinal axis of the needle guard device;

FIGS. 6A-D show a fixing and guide mechanism of the needle guard deviceat a front view, along longitudinal sections A-A and B-B and aperspective view along a longitudinal axis of the fixing guidemechanism;

FIG. 7 shows a distal needle guard of the needle guard device;

FIG. 8 shows an unlocking element of the needle guard device;

FIG. 9 is a perspective diagram showing a needle holder of the needleguard device;

FIG. 10 shows the needle holder in longitudinal section;

FIG. 11 is a perspective diagram showing a proximal needle guard of theneedle guard device;

FIG. 12 shows the proximal needle guard in longitudinal section;

FIG. 13 shows an embodiment of a lock mechanism of the needle guarddevice, with the proximal needle guard in a proximal initial position;

FIG. 14 shows the lock mechanism, with the proximal needle guard in areleasing position;

FIG. 15 shows the lock mechanism, with the proximal needle guard in aguard position;

FIG. 16 is a diagram on a larger scale showing the lock mechanism, withthe proximal needle guard in two different positions;

FIG. 17 shows components of a needle guard device based on a secondembodiment in accordance with the present invention;

FIG. 18 shows the distal needle guard of the second embodiment;

FIG. 19 is a perspective diagram showing a needle holder of the secondembodiment;

FIG. 20 shows the needle holder of the second embodiment in longitudinalsection;

FIG. 21 is a perspective diagram showing an unlocking element of thesecond embodiment;

FIG. 22 is a plan view in the distal direction showing the unlockingelement of the second embodiment;

FIG. 23 shows a proximal needle guard of the second embodiment;

FIG. 24 shows a lock mechanism of the second embodiment in an initialstate prior to an injection;

FIG. 25 shows the lock mechanism of the second embodiment in an endstate after an injection;

FIG. 26 shows the needle guard device of the second embodiment in theinitial state;

FIG. 27 shows the needle guard device of the second embodiment in astate during an injection; and

FIG. 28 shows the needle guard device of the second embodiment in theend state.

DETAILED DESCRIPTION

With regard to fastening, mounting, attaching or connecting componentsof the present invention, unless specifically described as otherwise,conventional mechanical fasteners and methods may be used. Otherappropriate fastening or attachment methods include adhesives, weldingand soldering, the latter particularly with regard to the electricalsystem of the invention, if any. In embodiments with electrical featuresor components, suitable electrical components and circuitry, wires,wireless components, chips, boards, microprocessors, inputs, outputs,displays, control components, etc. may be used. Generally, unlessotherwise indicated, the materials for making the invention and/or itscomponents may be selected from appropriate materials such as metal,metallic alloys, ceramics, plastics, etc. Generally, unless otherwiseindicated, relative positional or orientational terms (e.g., upwardly,downwardly, above, below, etc.) are intended to be descriptive, notlimiting.

FIG. 1 is a plan view onto a distal end face illustrating a needle guarddevice based on a first embodiment of the present invention. Threelongitudinal planes are indicated, A-A, B-B and C-C.

FIG. 2 is a view in longitudinal section A-A indicated in FIG. 1,showing the needle guard device based on the first embodiment. FIG. 3 isa view of the needle guard in longitudinal section B-B and FIG. 4illustrates longitudinal section C-C.

FIGS. 1 to 4 illustrate the needle guard device in an initial state,which it assumes or is in prior to being used for the first time. Inthis state, the needle guard device may be supplied to the user in asuitable sterile packaging, not illustrated. The needle guard devicecomprises an injection needle 1 in the form a straight, hollow cannulaand a needle holder 2, which fixedly retains the injection needle 1 in amiddle needle portion so that the injection needle 1 is not able to moveaxially, i.e. in the longitudinal direction L, and is also not able torotate. The needle holder 2 has a base 9 and a retaining region 10,which projects centrally out from the base 9 and holds the injectionneedle 1. The injection needle 1 extends through the retaining region 10of the needle holder 2. It projects beyond the retaining region 10 by aninjection portion 1 a in the distal direction and by a connectingportion 1 b in the proximal direction.

The needle holder 2 is inserted in a sleeve-shaped fixing and guidemechanism and secured so that it is not able to move. The needle holder2 divides the fixing and guide mechanism into a proximal fixing portion3 and a distal guide portion 4. The needle injection portion 1 a extendsbeyond the guide portion 4 in the distal direction by a length suitablefor administering subcutaneous injections. The fixing portion 3constitutes a fixing mechanism to provide a releasable attachment to adistal end of an injection device. The fixing mechanism may have one ormore catch elements to provide a catch connection to the injectiondevice. Alternatively, the fixing mechanism of the needle guard devicemay also have a screw thread or a bayonet fitting. The fixing portion 3surrounds the needle connecting portion 1 b and extends beyond it in theproximal direction. The guide portion 4 acts as a non-rotatable, axialguide for a distal needle guard 5, which in the initial state assumes adistal initial position relative to the needle holder 2 in which itextends beyond the guide portion 4 and distal tip of the injectionneedle 1. The distal needle guard 5 is a sleeve-shaped body extendingcircumferentially around the injection portion 1 a and simultaneouslyalso acts as a visual guard so that the user is not able to see theinjection portion 1 a. The distal needle guard 5 is biased by a springelement 6 by spring force acting in the distal direction. In the distalinitial position, the distal needle guard 5 is retained against theforce of the spring element 6 relative to the guide portion 4 by anunlocking element 8.

FIGS. 5 to 8 illustrate how the distal needle guard 5 co-operates withthe unlocking element 8 and the guide portion 4. In FIG. 5, thecomponents of the needle guard device are aligned one after the otheralong its central longitudinal axis L in the order in which they areassembled. The injection needle 1 is shown released from the needleholder 2 but may already be fixedly connected to the needle holder 2 atthe time of assembly.

FIGS. 6A-D shows the fixing and guide mechanism (which may be thought ofas comprising elements 3, 4) from a front view (FIG. 6A), twolongitudinal sections A-A (FIG. 6B) and B-B (FIG. 6C) and a perspectiveview (FIG. 4D). The fixing and guide mechanism has two recesses 4 a inits guide portion 4 at the distal end in an internal face extendingcircumferentially about the longitudinal axis L. At their proximal end,the recesses 4 a merge into the internal face via a steep shoulder. Thetwo shoulders each form a translation stop 4 c pointing in the distaldirection. Disposed to the side of the recesses 4 a are respectiveaxially extending guides 4 b to ensure that the distal needle guard 5 isguided in a straight line. Two other recesses 4 d are provided at thedistal end of the guide portion 4 in the same internal face, which areoffset from the recesses 4 a on the circumference of the internal faceby 90° in each case. The recesses 4 d each merge into the internal facevia a steep shoulder at their distal end. The two shoulders each form atranslation stop 4 e pointing in the proximal direction.

FIG. 7 shows the distal needle guard 5. The distal needle guard 5 hasaxial guides 5 b, which co-operate with the guides 4 b of the guideportion 4 and with them guide the distal needle guard 5 linearly butprevent it from rotating. Disposed at the proximal end of the distalneedle guard 5, two orifices O are provided in its casing, offset fromone another in the circumferential direction by 180°. A projection 5 cprojects respectively in the proximal direction into the orifices O,which axially lengthens the casing of the distal needle guard 5 in therespective orifice. The internal faces of the projections 5 b areoutwardly inclined in the proximal direction towards free ends of theprojections 5 b and, in the embodiment illustrated as an example, eachhas a constant inclination. They each form a ramp in co-operation withthe unlocking element 8. The distal needle guard 5 has two lockingelement elements 5 a on its proximal end offset from one another in thecircumferential direction by 180°, which are provided in the form ofresilient lugs in the embodiment illustrated as an example. The lockingelements 5 a are outwardly inclined in the proximal direction. Finally,two locating elements 5 d in the form of outwardly projecting cams areprovided on the external circumference of the distal needle guard 5,likewise at its proximal end offset from one another by 180° in thecircumferential direction.

FIG. 8 illustrates an embodiment of the unlocking element 8. Theunlocking element 8 has an annular base 22 at its proximal end.Projecting out from the base 22 in the distal direction are two fingers23, each of which has a projection 24 extending outwardly from itsdistal end. When the needle guard device is in the initial state, theprojections 24 extend through the orifices of the distal needle guard 5,as illustrated in FIG. 4, and hold the distal needle guard 5 in itsdistal initial position against the spring force of the spring element 6due to the spring element 6 pushing the outer ends of the projections 24into abutment with contact surfaces of the guide portion 4. Like theprojections 5 c of the distal needle guard 5, the projections 24 areinclined to form a ramp shape and their inclination is adapted to thatof the projections 5 c.

As may be seen from FIGS. 2 to 4, not only does the needle guard devicehave the distal needle guard 5, it also has a proximal needle guard 7for the connecting portion 1 b of the injection needle 1. The unlockingelement 8 co-operates with both the distal needle guard 5 and theproximal needle guard 7. In co-operation with the distal needle guard 5,it fulfils the described locking function. In co-operation with theproximal needle guard 7, it fulfils an unlocking function because in itsinitial position illustrated in FIGS. 2 to 4, it prevents a movement ofthe proximal needle guard 7 in the distal direction from being blocked.To enable co-operation with the proximal needle guard 7, two axiallyextending recesses formed as an axially extending track 25 are providedin the internal face of the base 22 of the unlocking element 8 offsetfrom one another in the circumferential direction by 180°, in which theproximal needle guard 7 locates in its initial position.

FIGS. 9 and 10 illustrate the needle holder 2 and FIGS. 11 and 12illustrate the proximal needle guard 7. The proximal needle guard 7 hasan annular base 14 at its proximal end and locking elements 15projecting out from the base 14 in the distal direction. The lockingelements 15 are finger-shaped or rod-shaped. In the embodimentillustrated as an example, these are two locking elements which projectout from a distal end face of the base 14 and are offset from oneanother by 180° in the circumferential direction about the longitudinalaxis L so that they enclose the needle connecting portion 1 b betweenthem when the proximal needle guard 7 is in the proximal initialposition. The base 14 has a central passage P for the needle connectingportion 1 b.

Disposed in a distal portion of the proximal needle guard 7, the lockingelements 15 have several projections, each extending outwards from thelocking elements, in this example three projections 16, 17 and 18. Thelocking elements 15 also each have a support 21 for the spring element6. The supports 21 are formed by projections extending radially inwardlytoward one another at the distal ends of the locking elements 15. Thespring element 6 is supported on the proximal needle guard 7 in theproximal direction by means of the supports 21, in other words isclamped or held between the distal needle guard 5 and the proximalneedle guard 7.

In the assembled state, the base 14 of the proximal needle guard 7 isdisposed proximally of the base 9 of the needle holder 2 and therod-shaped or finger-shaped locking elements 15 extend in the distaldirection through two passages 11 formed in the base 9 of the needleholder 2. In the proximal initial position, the distal projections 16absorb the force of the spring element 6. To this end, the projections16 respectively form a stop pointing in the proximal direction which ispushed by the spring element 6 against a complementary stop 13 (FIG. 10)of the needle holder 2, which is formed by the base 9 of the needleholder 2 in the embodiment illustrated as an example. The projection 17acts as another stop 20 pointing in the proximal direction. Theprojection 18 acts as yet another stop 19 but pointing in the distaldirection.

FIGS. 13, 14 and 15 illustrate the different positions which theproximal needle guard 7 assumes relative to the needle holder 2 when theneedle guard device is connected to the injection device and whendetached from the injection device again after an injection. In FIG. 13,the proximal needle guard 7 has assumed its proximal initial position.It can be moved from the initial position against the force of thespring element 6 relative to the needle holder 2 and to the unlockingelement 8 disposed in an unlocking position as far as a releasingposition illustrated in FIG. 14, in which the needle connecting portion1 b extends beyond the proximal needle guard 7 in the proximaldirection. In FIG. 15, the proximal needle guard 7 has assumed a guardposition in which it is locked relative to the needle holder 2 so thatit can not be moved out of the guard position back into the releasingposition. To produce the lock, the needle holder 2 and the proximalneedle guard 7 form a lock mechanism with locking elements in a lockedengagement, namely on the two locking elements 15 of the proximal needleguard 7 and the base 9 of the needle holder 2 acting as a lockingelement. A result, the proximal needle guard 7 can be moved into thereleasing position once only, namely by a force expended on the proximalneedle guard 7 in the distal direction, and automatically moves due tothe spring force of the spring element 6, as the external forcedecreases, back in the proximal direction as far as the locked guardposition. In the guard position, it extends beyond the distal tip of theneedle connecting portion 1 b in the distal direction and thus protectsthe user against injuries caused by piercing. In the embodimentillustrated as an example, a particularly reliable guarding action isprovided due to the annular base 14 of the proximal needle guard 7, thecentral passage of which is so narrow that the connecting needle is ableto fit through the passage when attached to the injection device but theuser cannot reach the distal needle tip through the passage.

FIG. 16 illustrates two states of the components which co-operate tomove the proximal needle guard 7. In the left-hand half of FIG. 16, theproximal needle guard 7 has assumed the distal initial position and inthe right-hand half, the locked guard position. The left-hand halfcorresponds to the state illustrated in FIGS. 2 to 4 and FIG. 13 and theright-hand half of FIG. 16 corresponds to the state illustrated in FIG.15.

In the initial position, the projections 16 hold the proximal needleguard 7 on the needle holder 2. The projections 17 taper in an arrowshape in the distal direction whilst the projections 18 taper in anarrow shape in the proximal direction. The stops 19 and 20 of theprojections 17 and 18 are disposed axially facing one another. When theneedle guard device is attached to an injection device by the fixingportion 3, for example is screwed on or clipped on, the proximal needleguard 7 moves into contact with the distal end of the injection deviceand is pushed in the distal direction against the force of the springelement 6 during the attachment operation. During this movement, theprojections 17 slide by their arrow-shaped distal faces through thepassages 11 of the needle holder 2 so that the locking elements 15 arebent elastically inward. As soon as the projections 17 have movedthrough the passages 11, they move into contact with the axial guidetracks 25 of the unlocking element 8. The locking elements 15 thusremain in the bent state, for which purpose the passages 11 offer a wayof axially extending the guide tracks 25. The projections 17 extendfarther outward than the following projections 18 which now move intothe region of the passages 11. The extra distance of the projections 17measured transversely to the longitudinal axis L is long enough for theprojections 20 in contact with the guide tracks 25 to hold the lockingelements 15 far enough away from the outer edge of the passages 11 toenable the projections 18 to be moved in the distal direction, likewisethrough the passages 11. Once the projections 18 have also moved throughthe passages 11, the proximal needle guard 7 moves farther in the distaldirection due to the contact with the injection device until theproximal needle guard 7 assumes the releasing position illustrated inFIG. 14, once the connection to the injection device is established. Atthe same time as the injection device is attached, the needle connectingportion 1 b pierces a sealing membrane on a distal end of a medicamentreservoir and thus establishes a flow connection between the medicamentreservoir and the proximal tip of the needle injection portion 1 a.

When the needle guard device is detached from the injection device andpressure on the proximal needle guard 7 is thus released, the springelement 6 pushes the proximal needle guard 7 in the proximal direction.The proximal projections 18 firstly move into contact with the base 9forming the locking element of the needle holder 2 so that the lockingelements 15 are bent elastically inward again and the passages 11 areable to move in the proximal direction. As illustrated in FIG. 16, theguide track 25 of the unlocking element 8 may be sufficiently long inthe axial direction to enable the projections 18 extending radiallyoutward the farthest to pass the unlocking element 8 during the movementof the proximal needle guard 7 into the guard position. Alternatively,if the guide tracks 25 are short, as is the case with the exemplaryunlocking element illustrated in FIGS. 8-15, the projections 18 arerounded at their outer ends or may be inclined, as in the embodimentillustrated as an example in FIG. 16 and also in FIGS. 12 and 14. In theend state after use illustrated in the right-hand half of FIG. 16, theprojections 18 with their respective stop 19 in co-operation with thebase or locking element 9 prevent the proximal needle guard 7 from beingable to move in the distal direction again relative to the needle holder2.

According to some embodiments, the needle guard device may be used asfollows. The user attaches the needle guard device in the initial stateillustrated in FIGS. 2 to 4 to an injection device by connecting thefixing portion 3 to the distal end of the injection device. During theconnection process, the injection device pushes in the distal directionagainst the proximal needle guard 7, causing the latter to move into thereleasing position illustrated in FIG. 14. At the same time, theinjection needle 1 pierces the sealing membrane of the medicamentreservoir in the region of its connecting portion 1 b and establishesthe flow connection to the proximal needle tip. When the needle guarddevice is attached to the injection device, the spring element 6 pushesthe proximal needle guard 7 loosely against a point on the distal end ofthe injection device, for example against a terminal edge of the deviceor medicament reservoir. The distal needle guard 5 extends with itslocking element 5 a (FIG. 7) into the guide portion 4 so that thelocking elements 5 a are not able to fulfil any locking function in thisstate and the distal needle guard 5 is able to move freely against theforce of the spring element 6 in the proximal direction.

For the actual injection, the user then places the injection device onthe desired injection point on the skin by the distal end, which is nowformed by the distal needle guard 5, and moves the injection device inthe distal direction relative to the distal needle guard 5. The distalneedle guard 5 moves under the pressing force and against the force ofthe spring element 6 in the proximal direction deeper into the guideportion 4. Simultaneously at the start of this movement, the ramp-shapedprojections 5 c of the distal needle guard 5 (FIG. 7) slide across theadapted ramp-shaped projections 24 of the unlocking element 8 (FIG. 8)so that its fingers 23 are elastically bent in the direction towards thecentral longitudinal axis L. During the remaining movement of the distalneedle guard 5 in the proximal direction, the projections 24 slide inthe axial direction across the internal face of the distal needle guard5. During this sliding movement, the fingers 23 of the unlocking element8 are constantly bent elastically inwardly and push against the internalface of the distal needle guard 5 with an elastic force. The distalneedle guard 5 moves completely into the guide portion 4 so that theinjection needle 1 penetrates the skin and the subcutaneous tissue byits entire injection portion 1 a extending out from the guide portion 4.Full insertion of the distal needle guard 5 in the guide portion 4 maymake the needle injection portion 1 a as short as possible, but is notnecessary.

After administering the medicament, the user moves the injection deviceaway from the injection point so that the distal needle guard 5 movesback in the distal direction under the effect of the spring element 6.Since the unlocking element 8 is connected to the distal needle guard 5due to a non-positive connection via the projections 24 and theelastically bent fingers 23, the distal needle guard 5 drives theunlocking element 8 with it as it moves in the distal direction so thatthe unlocking element 8 is lifted from the base 9 of the needle holder 2and is moved relative to the proximal needle guard 7 into a neutralposition. Since the projections 24 no longer extend through the distalneedle guard 5, the distal needle guard 5 moves beyond the distalinitial position relative to the guide portion 4 in the distaldirection. As soon as the locking elements 5 a of the distal needleguard 5 have passed the stops 4 c of the guide portion 4 (FIG. 6), theysnap outward into the recesses 4 a and lock the distal needle guard 5 ina distal guard position, preventing a movement back in the proximaldirection. The locating elements 5 d move into the recesses 4 d andco-operate with the stops 4 e to hold the distal needle guard 5 on theguide portion 4. Instead of the unlocking element 8 holding theprojections 24 on the distal needle guard 5 by only a non-positiveconnection (e.g., frictional contact), the engagement could also bebased on a positive connection, in which case the unlocking element 8would latch with the distal needle guard 5 by the projections 24.However, it the connection may be established early via the describednon-positive connection.

To administer another injection, the user releases the needle guarddevice from the injection device with the distal needle guard 5 lockedin its guard position. During the releasing process, the needle holder 2moves in the distal direction relative to the injection device. Theproximal needle guard 7 moves in the proximal direction relative to theneedle holder 2 under the effect of the spring element 6. As soon as theprojections 18 of the proximal needle guard 7 have passed the passages11 in the base 9, i.e. the passages 11 of the locking element of theneedle holder 2, the locking elements 15 of the proximal needle guard 7snap elastically outward. In this state illustrated in the right-handhalf of FIG. 16, the stops 20 of the big projections 17 hold theproximal needle guard 7 on the needle holder 2 against the force of thespring element 6 and the stops 19 of the proximal projectionsco-operating with the complementary stops 12 of the needle holder 2prevent the proximal needle guard 7 from being able to move in thedistal direction again. The two stops 19 and 20 clamp the base 9 of theneedle holder 2 in a close fit between them, and the clearance isideally just enough to ensure that the short snapping or pivotingmovement of the locking elements 15 is not prevented. However, the playmay be greater, provided allowance is made for the proximal needle guard7 to move axially. Such an ability to move should not be so great thatthe distal tip of the injection needle 1 is able to project out from theproximal needle guard 7.

FIG. 17 shows a needle guard device based on a second embodiment withits components aligned longitudinally along a central longitudinal axisL in the order in which they are assembled. The needle guard deviceagain comprises an injection needle 1 which is held by a needle holder2, as was the case with the embodiment illustrated as a first example, afixing and guide mechanism 3, 4 for attaching the needle guard device tothe distal end of an injection device and providing an axial guide for adistal needle guard 5 as well as a spring element 6. As regards the wayin which these components co-operate, the needle guard device of thisembodiment corresponds to the embodiment illustrated as a first example.The fixing and guide mechanism is substantially similar to thatdescribed in connection with the first embodiment. The needle guarddevice also has a distal needle guard 27 and an unlocking element 30,which differ in terms of function from the same components 7 and 8 ofthe first embodiment, due to the way in which they co-operate with theother components.

FIG. 18 illustrates the distal needle guard 5′ of the second embodiment.The distal needle guard 5′ of the second embodiment is missing the twoorifices with the projections 5 c but otherwise corresponds to thedistal needle guard 5 of the first embodiment except that there is asmaller geometric deviation in the case of the locating elements 5 d′.The locating elements 5 d′ each have an inclination with respect to thelongitudinal axis L on a side pointing in the circumferential directionabout the longitudinal axis L so that the respective locating element 5a′ forms a ramp at the relevant side.

FIGS. 19 and 20 illustrate the needle holder 2′ of the secondembodiment. The needle holder 2′ again has a base 9′ and a centralretaining region 10′ for an injection needle 1 to be arranged in base9′. As with the first embodiment, the base 9′ is provided with twopassages 11′ through which the needle guard 27 can move in the proximaldirection into its guard position and which also serve as a means oflocking the needle guard 27 in the guard position. Projecting outwardfrom the base 9′ in the distal direction adjacent to the retainingregion 10′ are two projections 26 a offset from one another by 180° inthe circumferential direction about the longitudinal axis L, each ofwhich is inclined on one side to form a ramp. Facing the ramp-shaped,inclined sides of the projections 26 a, a respective projection 26 balso extends out from the base 9′ in the distal direction. The plane ofthe section illustrated in FIG. 20 extends through the longitudinal axisL and through the gaps between each one of the projections 26 a and theprojection 26 b facing the respective ramp.

FIG. 21 is a perspective view illustrating the unlocking element 30.FIG. 22 is a plan view showing a bottom face of the unlocking element30, i.e. a view in the distal direction. The unlocking element 30 is ofa hollow cylindrical design. Two recesses 31 are provided in the casingof the unlocking element 30 offset from one another by 180° in thecircumferential direction, which extend through the casing and form aguide track 32 inclined on one side in the circumferential direction forone of the locating elements 5 d′ of the distal needle guard 5′. Arespective projection 33 extends out from a distal edge of the unlockingelement 30 into the respective recess 31. The two recesses 31 arecircumferentially framed by the casing of the unlocking element 30 and arecess 35 is provided respectively on the internal face of the casingdistally in front of the guide tracks 32 which extends from the distalend of the unlocking element 30 continuously into the respective recess31. When the needle guard device is being assembled, the unlockingelement 30 with its two recesses 35 is moved across the locatingelements 5 d′ of the distal needle guard 5′ so that the locatingelements 5 d′ move into the respective co-operating recess 31. Byturning the unlocking element 30, likewise during the course ofassembly, the locating elements 5 d′ are then moved in thecircumferential direction behind the respective projection 33 into thecircumferential region 34 so that the locating elements 5 d′ locatebehind the distal edge of the unlocking element 30 in itscircumferential regions 34 and hold the distal needle guard 5′ on theguide portion 4 against the force of the spring element 6 as a result.The unlocking element 30 is able to move in the distal direction so thatit abuts with the guide portion 4 but is not able to move backward andforward between this abutting position and the base 9′ of the needleholder 2′, nor is it able to rotate relative to the needle holder 2′about the longitudinal axis L.

The unlocking element 30 has an annular base 36 projecting radiallyinwardly on its bottom face at the proximal end of its casing andlocating elements 37 projecting out from the base 36 in the proximaldirection, in total two locating elements 37, which are offset from oneanother by 180° in the circumferential direction. Two passages 38 forthe proximal needle guard 27 are provided in the base 36, offset fromone another by 180° in the circumferential direction.

FIG. 23 illustrates the proximal needle guard 27. The needle guard 27has an annular base at a distal end and flexible legs or fingersprojecting elastically out from the base in the direction towards thelongitudinal axis L, which constitute the locking elements 28 of theneedle guard 27. A projection 29 is respectively formed on the externalface of the locking elements 28. The projections 29 taper in an arrowshape in the proximal direction and, as was the case with theprojections 17 of the first embodiment, respectively form a stop of theneedle guard 27 pointing in the distal direction. In this respect,reference may be made to the explanation given in connection with thefirst embodiment.

FIG. 24 illustrates the components of the lock mechanism of the secondembodiment which co-operate to lock the needle guard 27, with the needleguard 27 assuming a distal initial position which simultaneously alsocorresponds to the releasing position of the needle guard 27. In thesecond embodiment, when the needle guard 27 is in the initial position,it already is completely behind the connecting portion 1 b of theinjection needle 1 in the distal direction. It is also behind the base9′ of the needle holder 2′, i.e. the spring element 6 pushes the needleguard 27 towards the base 9′ in the proximal direction in the initialposition. The locking elements 28 extend through the passages 38 of theunlocking element 30 (FIG. 22). When the needle guard device is in theinitial state, the passages 38 and the passages 11 of the needle holder2′ are offset from one another in the circumferential direction. Thelocating elements 37 of the unlocking element 30 axially face theramp-shaped sides of the projections 26 a of the needle holder 2′. Thespring element 6 holds the unlocking element 30 in the illustrateddistal initial position illustrated in FIG. 24 via the distal needleguard 5′ because the distal needle guard 5′ locates behind the unlockingelement 30 in the circumferential regions 34 by its locating elements 5d′ and pulls it into the distal initial position, thereby moving it intoabutment against the guide portion 4. This initial state is alsoillustrated in FIG. 26.

FIG. 25 illustrates the components of the lock mechanism in the endstate after the needle guard device has been used and with the needleguard 27 disposed in its proximal guard position. FIG. 28 illustratesthe needle guard device as a whole, likewise in its end state.

A description will be given below of how the needle guard device of thesecond embodiment works with reference to FIGS. 26 to 28 but also withreference to the other drawings of FIGS. 17 to 25, particularly FIGS. 24and 25.

The needle guard device is connected to the injection device in theinitial state illustrated in FIGS. 24 and 26, for example screwed to itor clipped onto it. As this happens, the needle connecting portion 1 bpierces the sealing membrane of the medicament reservoir. A movement ofthe needle guard 27 does not yet take place during the fitting process.

The user then pierces the skin through to the subcutaneous tissue at thedesired injection point with the injection needle 1. As this happens,the distal needle guard 5′ moves in the proximal direction relative tothe needle holder 2′ so that, conversely, the needle injection portion 1a projects forward. FIG. 27 illustrates the needle guard device in thepiercing state whilst the medicament is being administered.

As the distal needle guard 5′ moves in the proximal direction, thelocating elements 5 d′ move along the respective associated guide track32 of the unlocking element 30. The inclination of the guide track 32 isselected so that there is no or practically no inhibiting effect. As aresult of this guide engagement, the unlocking element 30 is rotated outof its angular position illustrated in FIG. 24, the unlocking position,into the angular position (neutral position) illustrated in FIG. 25. Therotating movement is superimposed by an axial translating movementduring which the locating elements 37 of the unlocking element 30 slideon the ramp-shaped side of the respective co-operating projection 26 a.The translating and rotating movement is restricted by an abuttingcontact of the locating elements 37 and the projections 26 b. Theunlocking element 30 drives the needle guard 27 with it during therotating movement because the locking elements 28 extend through thepassages 38. As soon as the unlocking element 30 has reached its neutralposition illustrated in FIG. 25, the passages 38 of the unlockingelement 30 (FIG. 22) overlap the passages 11′ of the needle holder 2′(FIGS. 19 and 20) to the degree that the locking elements 28 of theneedle guard 27 are able to pass through the passages 11′ due to theforce of the spring element 6. The locking elements 28 are pushed by thespring element 6 against a point on the distal end of the injectiondevice, for example a distal point of the device itself or themedicament reservoir. Once they have moved into the passages 11 of theneedle holder 2, the locking elements 28 prevent the unlocking element30 from being able to turn back into its unlocking position (FIG. 24).

When the injection needle 1 has been pulled out of the tissue andpressure has thus been relieved on the distal needle guard 5′, thespring element 6 moves the distal needle guard 5 in the distaldirection. The position of the two projections 33 in the circumferentialdirection relative to the respective facing guide track 32 is selectedso that the locating elements 5 d are able to move into the recesses 35as the distal needle guard 5 moves in the distal direction, therebycausing the distal needle guard 5′ to be finally released by theunlocking element 30, and the locking elements 5 a′ are able to moveinto the recesses 4 a of the guide portion 4 (FIG. 6), as was the casewith the first embodiment, and lock the distal needle guard 5′ in itsdistal guard position to prevent it from moving in the proximaldirection due to the lock engagement with the stops 4 c. As with thefirst embodiment, the locating elements 5 d co-operate with the stops 4e (FIG. 6) to ensure that the distal needle guard 5′ can not becompletely extracted from the guide portion 4 in the distal direction.

The needle guard device is released from the injection device with thedistal needle guard 5′ locked. The proximal needle guard 27 moves in theproximal direction relative to the needle holder 2′ into the guardposition illustrated in FIG. 25 and FIG. 26 under the effect of thespring element 6. In the guard position, the locking elements 28 extendbeyond the tip of the needle connecting portion 1 b in the proximaldirection. The needle guard 27 is locked by a lock engagement betweenits projections 29 and the base 9′ of the needle holder 2′ to prevent amovement back in the distal direction. The needle guard 27 is supportedby its annular base on the base 9′ of the needle holder 2′ in theproximal direction.

Embodiments of the present invention, including preferred embodiments,have been presented for the purpose of illustration and description.They are not intended to be exhaustive or to limit the invention to theprecise forms and steps disclosed. The embodiments were chosen anddescribed to provide the best illustration of the principles of theinvention and the practical application thereof, and to enable one ofordinary skill in the art to utilize the invention in variousembodiments and with various modifications as are suited to theparticular use contemplated. All such modifications and variations arewithin the scope of the invention as determined by the appended claimswhen interpreted in accordance with the breadth they are fairly,legally, and equitably entitled.

1-17. (canceled)
 18. A needle guard device releasably attachable to aninjection device, the needle guard device comprising: a first needleguard movable from a first position into a guard position; a secondneedle guard movable relative to the needle holder from a first positioninto a guard position; and a lock for preventing movement of the secondneedle guard relative to the first needle guard when the second needleguard is in its guard position, wherein the lock comprises a portion ofthe second needle guard.
 19. The needle guard device of claim 18,wherein in the first position of at least one of the first and secondneedle guard, the at least one needle guard is in a retracted position,and in the guard position, the at least one needle guard is in anextended position.
 20. The needle guard device of claim 18, furthercomprising: an injection needle comprising an injection portion and aconnecting portion; and a needle holder, from which the injectionportion of the injection needle extends in a first direction and fromwhich the connecting portion of the injection needle extends in a seconddirection opposite the first direction.
 21. The needle guard device ofclaim 20, wherein the first needle guard is arranged behind theinjection portion of the injection needle in its first position, andoverlaps the injection portion including the injection tip of theinjection needle in its guard position.
 22. The needle guard device ofclaim 20, wherein the second needle guard overlaps the connectingportion of the injection needle including the connecting tip of theinjection needle at least in its guard position.
 23. The needle guarddevice of claim 20, wherein the lock further comprises a passage formedby and extending through the needle holder for cooperating with at leasta portion of the lock formed by the second needle guard, wherein in theguard position of the second needle guard, the second needle guard atleast partially extends through the needle holder by the passage. 24.The needle guard device of claim 23, wherein the lock further comprisescooperating projections and stops, wherein the needle holder comprisesone of the cooperating stops and projections and the needle guardcomprises the other of the cooperating stops and projections, and in theguard position of the second needle guard, the cooperating projectionsand the stops engage to block movement of the second needle guard out ofits guard position.
 25. The needle guard device of claim 20, furthercomprising a fixing sleeve for housing the needle holder within aninterior of the fixing sleeve.
 26. The needle guard device of claim 18,wherein movement of the first needle guard from its first positiontowards its guard position enables the second needle guard to move toits guard position.
 27. The needle guard device of claim 26, wherein thesecond needle guard is urged from its first position to its guardposition by a spring element.
 28. The needle guard device of claim 27,wherein the spring element urges the second needle guard to its guardposition upon detaching the needle guard device from the injectiondevice.
 29. The needle guard device of claim 26, wherein the secondneedle guard is releasably held in its first position, and whereinmovement of the first needle guard towards its guard position causes thesecond needle guard to be released and enables the second needle guardto move to its guard position.
 30. The needle guard device of claim 29,wherein the second needle guard is urged to its guard position by aspring element.
 31. The needle guard device of claim 30, wherein thespring element urges the second needle guard to the guard position upondetaching the needle guard device from the injection device.
 32. Theneedle guard device of claim 29, wherein the needle guard device furthercomprises a needle holder and cooperating stops and projections, whereinthe needle holder comprises one of the cooperating stops and projectionsand the second needle guard comprises the other of the cooperating stopsand projections, and wherein the second needle guard is releasably heldin its first position by the cooperating stops and projections.
 33. Theneedle guard device of claim 18, wherein in the guard position of thefirst needle guard, the first needle guard is blocked from moving to itsfirst position.
 34. The needle guard device of claim 33, wherein thefirst needle guard is urged to its guard position by a spring element.35. A needle guard device releasably attachable to an injection device,the needle guard device comprising: an injection needle comprising aninjection portion and a connecting portion; a needle holder, from whichthe injection portion of the injection needle extends in a firstdirection and from which the connecting portion of the injection needleextends in a second direction opposite from the first direction; a firstneedle guard assembly, the first needle guard assembly comprising afirst needle guard and an unlocking element movable relative to theneedle holder from a first position into a guard position, wherein atleast a portion of the first needle guard assembly is arranged behindthe injection portion of the injection needle in the first position andat least a portion of the first needle guard assembly overlaps theinjection portion of the injection needle in the guard position; asecond needle guard movable relative to the needle holder from a firstposition into a guard position, the second needle guard overlapping theconnecting portion of the injection needle at least in its guardposition; and a lock for blocking a movement of the second needle guardout of its guard position into its first position, wherein the secondneedle guard comprises a portion of the lock and the needle holdercomprises another portion of the lock.
 36. The needle guard device ofclaim 35, wherein movement of at least a portion of the first needleguard assembly towards its guard position enables the second needleguard to move towards its guard position.
 37. The needle guard device ofclaim 36, wherein the second needle guard is arranged behind theconnecting portion of the injection needle in its first position. 38.The needle guard device of claim 37, wherein the second needle guard isurged from its first position to its guard position by a spring element.39. The needle guard device of claim 38, wherein the spring elementurges the second needle guard to its guard position upon detaching theneedle guard device from the injection device.
 40. The needle guarddevice of claim 35, wherein the second needle guard is releasably heldin the first position and movement of at least a portion of the firstneedle guard assembly towards the guard position releases the releasablyheld second needle guard and enables the released second needle guard tomove to its guard position.
 41. The needle guard device of claim 40,wherein the second needle guard is urged to its guard position by aspring element.
 42. The needle guard device of claim 41, wherein thespring element urges the second needle guard to its guard position upondetaching the needle guard from the injection device.
 43. The needleguard device of claim 35, further comprising a fixing sleeve for housingat least a portion of the needle holder within an interior of the fixingsleeve.
 44. The needle guard device of claim 43, wherein at least aportion of the first needle guard assembly is movably coupled to thefixing sleeve.
 45. The needle guard device of claim 35, wherein thesecond needle guard is movably coupled to the needle holder.
 46. Aneedle guard device releasably attachable to an injection device, theneedle guard device comprising: an injection needle comprising aninjection portion and a connecting portion; a needle holder, from whichthe injection portion of the injection needle extends in a firstdirection and from which the connecting portion of the injection needleextends in a second direction opposite from the first direction; a firstneedle guard assembly comprising a first needle guard and an unlockingelement movable relative to the needle holder, wherein the first needleguard and the unlocking element are configured to rotate relative to oneanother to enable the first needle guard assembly to move to the guardposition in which at least a portion of the first needle guard assemblyoverlaps the needle injection portion of the injection needle; a secondneedle guard movable relative to the needle holder from a first positioninto a guard position, the second needle guard arranged behind theconnecting portion of the injection needle in the first position andoverlaps the connecting portion of the injection needle in the guardposition; and a lock for blocking a movement of the second needle guardout of its guard position into its first position, wherein the lockcomprises a portion of the second needle guard and a portion of theneedle holder.
 47. The needle guard device of claim 46, wherein relativerotation of the first needle guard and the unlocking element enables thesecond needle guard to move to its guard position.
 48. The needle guarddevice of claim 46, wherein the second needle guard is releasably lockedin its first position, and wherein relative rotation between the firstneedle guard and the unlocking element releases the second needle guard.